package com.pony.shiro;

import cn.hutool.json.JSONUtil;
import com.baomidou.mybatisplus.core.toolkit.StringUtils;
import com.pony.common.Result;
import com.pony.util.JwtUtils;
import io.jsonwebtoken.Claims;
import org.apache.shiro.authc.AuthenticationException;
import org.apache.shiro.authc.AuthenticationToken;
import org.apache.shiro.authc.ExpiredCredentialsException;
import org.apache.shiro.web.filter.authc.AuthenticatingFilter;
import org.apache.shiro.web.util.WebUtils;
import org.springframework.stereotype.Component;
import org.springframework.web.bind.annotation.RequestMethod;

import javax.annotation.Resource;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;

/**
 * @author malf
 * @description 定义jwt的过滤器JwtFilter。
 * @date 2021/5/22
 * @project springboot_blog
 */
@Component
public class JwtFilter extends AuthenticatingFilter {
	@Resource
	JwtUtils jwtUtils;

	@Override
	protected AuthenticationToken createToken(ServletRequest servletRequest, ServletResponse servletResponse) throws Exception {
		// 获取 token
		HttpServletRequest request = (HttpServletRequest) servletRequest;
		String jwt = request.getHeader("Authorization");
		if (StringUtils.isEmpty(jwt)) {
			return null;
		}
		return new JwtToken(jwt);
	}

	@Override
	protected boolean onAccessDenied(ServletRequest servletRequest, ServletResponse servletResponse) throws Exception {
		HttpServletRequest request = (HttpServletRequest) servletRequest;
		String token = request.getHeader("Authorization");
		if (StringUtils.isEmpty(token)) {
			return true;
		} else {
			// 判断是否已过期
			Claims claim = jwtUtils.getClaimByToken(token);
			if (claim == null || jwtUtils.isTokenExpired(claim.getExpiration())) {
				throw new ExpiredCredentialsException("token已失效，请重新登录！");
			}
		}
		// 执行自动登录
		return executeLogin(servletRequest, servletResponse);
	}

	@Override
	protected boolean onLoginFailure(AuthenticationToken token, AuthenticationException e, ServletRequest request, ServletResponse response) {
		HttpServletResponse httpResponse = (HttpServletResponse) response;
		try {
			//处理登录失败的异常
			Throwable throwable = e.getCause() == null ? e : e.getCause();
			Result r = Result.fail(throwable.getMessage());
			String json = JSONUtil.toJsonStr(r);
			httpResponse.getWriter().print(json);
		} catch (IOException e1) {
		}
		return false;
	}

	/**
	 * 对跨域提供支持
	 */
	@Override
	protected boolean preHandle(ServletRequest request, ServletResponse response) throws Exception {
		HttpServletRequest httpServletRequest = WebUtils.toHttp(request);
		HttpServletResponse httpServletResponse = WebUtils.toHttp(response);
		httpServletResponse.setHeader("Access-control-Allow-Origin", httpServletRequest.getHeader("Origin"));
		httpServletResponse.setHeader("Access-Control-Allow-Methods", "GET,POST,OPTIONS,PUT,DELETE");
		httpServletResponse.setHeader("Access-Control-Allow-Headers", httpServletRequest.getHeader("Access-Control-Request-Headers"));
		// 跨域时会首先发送一个OPTIONS请求，这里我们给OPTIONS请求直接返回正常状态
		if (httpServletRequest.getMethod().equals(RequestMethod.OPTIONS.name())) {
			httpServletResponse.setStatus(org.springframework.http.HttpStatus.OK.value());
			return false;
		}
		return super.preHandle(request, response);
	}

}
